Only 30 percent of Medicare patients who received ventricular assist devices (VADs) in 2014 attended cardiac rehabilitation, but those patients enjoyed significant decreases in hospitalizations and mortality over the following year, according to a study in JACC: Heart Failure.

Cardiac rehab is recommended for patients with ischemic heart disease, heart failure with reduced ejection fraction (HFrEF) and for individuals following heart transplantation. VADs are not one of the indications covered by Medicare, but many VAD patients meet criteria for coverage under the HFrEF indication, wrote lead researcher Justin M. Bachmann, MD, MPH, and colleagues.

The authors studied 1,164 patients undergoing LVAD implantation in the U.S. in 2014. A total of 30 percent initiated cardiac rehab within the following year, with participation rates ranging from 25 percent in the Northeast to 38 percent in the Midwest. Compared to those not enrolled in rehab, any participation was associated with a 47 percent decrease in one-year mortality risk and a 23 percent reduction in one-year hospitalizations.

“Although it is not possible to account fully for all confounding variables, VAD recipients who participate in CR appear to have lower risks for hospitalization and mortality,” wrote Bachmann, with Vanderbilt University Medical Center, and coauthors. “These exploratory results suggest opportunities for further, more definitive studies of the effectiveness of CR in this population, as well as a need to understand factors that drive patient and caregiver decisions regarding CR participation.”

Bachmann et al. found the time from discharge to the first rehab appointment was 83 days, nearly double that of a recent study of patients with ischemic heart disease (42 days).

“This delay is likely attributable to the significant post-operative recovery period after VAD implantation, as well as the Medicare requirement that patients referred to CR programs for systolic heart failure be stable for six weeks (for example, no cardiovascular hospitalizations) before attending the first session,” they wrote.

Bachmann and colleagues believe this time interval warrants further evaluation to see whether it is affecting rehab participation.

On average, patients stopped two-thirds of the way through the recommended course of 36 rehabilitation sessions. Interestingly, younger patients attended fewer sessions. This may seem counterintuitive due to their lower burden of frailty and comorbidities, but the researchers pointed out younger LVAD recipients are also more likely to return to work and prioritize those responsibilities over attending rehab.

The authors attempted to eliminate a healthy cohort bias by adjusting their analyses for comorbidities but acknowledged the possibility of unobserved confounding. Still, they remained confident cardiac rehab decreased hospitalizations and mortality among the study population.

“Beyond CR’s known beneficial effects on skeletal muscle function, peak oxygen uptake, and health status in VAD recipients, CR offers an opportunity for health care professionals to monitor these patients serially, thus potentially averting unplanned hospitalizations,” Bachmann and coauthors wrote.

In an accompanying editorial, Chetan B. Patel, MD, and Kishan S. Parikh, MD—both cardiologists at Duke University Medical Center—said providers may not recommend cardiac rehab in some patients due to reasons uncaptured in the study such as inadequate social support or worsening right-side heart failure. They believe further research is necessary to highlight the reasons behind referral decisions and the geographic disparity seen in cardiac rehabilitation.

“The hope is that future mechanistic and randomized studies of exercise training in VAD-treated patients will provide important insights into the global physiological impact of heart failure and ways to optimize the journey to recovery,” they wrote.